<html>
  <head>
    <style>
      html { background:black; color:#45a0d0; }

      img.button { margin:20px; }
      img.button:hover 
      {
        outline:10px glow #45a0d0 10px; 
        foreground-image-transformation: contrast-brightness-gamma(0.5,0.6, 1.5);
      }
    </style>
  </head>
<body>
  <p>Move mouse over the image:</p>
  <img .button src=gel-btn.png /> 
</body>
</html>